Field Of The Invention
This invention relates to auxiliary locks of the type having a dead bolt extending through a faceplate for engagement with a locking hole.
An auxiliary lock is an extra reinforcing device for safety. When fixing this lock in a door, a long latitudinal groove needs to be cut on the side surface of the door so as to fit the lock in, and a turning hole then is cut in the front surface of the door to fit with the intersecting crossed hole of the lock. The "crossed hole" is a rotatable member having a cross-shaped opening.
Nowadays, locks, in order to meet different requirements depending on the structure of a door, are usually manufactured into two sizes--so called 60 mm and 70 mm. therefore manufacturers have to make auxiliary locks of different sizes, retailers are obliged to devote more space for storing them, and besides, buyers will feel puzzled how to select them.